/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso.channel;

import org.jpos.iso.*;

import java.io.BufferedReader;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Vector;

/**
 * Implements an ISOChannel suitable to be used to connect to an X.25 PAD.
 * It waits a limited amount of time to decide when a packet is ready
 * to be unpacked.
 * <p/>
 * This channel is based on PADChannel version 1.4. The new version
 * seems to have some problems dealing with ETXs (we're working on it).
 * Use this version _only_ if you have problems with current PADChannel
 * as it will be deprecated some time in the future.
 *
 * @author <a href="mailto:apr@cs.com.uy">Alejandro P. Revilla</a>
 * @version $Id$
 * @see ISOMsg
 * @see ISOException
 * @see ISOChannel
 */
@SuppressWarnings("unchecked")
public class X25Channel extends BaseChannel {
	BufferedReader reader = null;
	protected byte[] header;

	/**
	 * No-args constructor
	 */
	public X25Channel() {
		super();
	}

	/**
	 * Constructs client ISOChannel
	 *
	 * @param host server TCP Address
	 * @param port server port number
	 * @param p    an ISOPackager
	 * @see ISOPackager
	 */
	public X25Channel(String host, int port, ISOPackager p) {
		super(host, port, p);
	}

	/**
	 * Construct server ISOChannel
	 *
	 * @param p an ISOPackager
	 * @throws IOException
	 * @see ISOPackager
	 */
	public X25Channel(ISOPackager p) throws IOException {
		super(p);
	}

	/**
	 * constructs a server ISOChannel associated with a Server Socket
	 *
	 * @param p            an ISOPackager
	 * @param serverSocket where to accept a connection
	 * @throws IOException
	 * @see ISOPackager
	 */
	public X25Channel(ISOPackager p, ServerSocket serverSocket)
			throws IOException {
		super(p, serverSocket);
	}

	/**
	 * @return a byte array with the received message
	 * @throws IOException
	 */
	protected byte[] streamReceive() throws IOException {
		int c, k = 0, len = 1;
		Vector v = new Vector();

		c = serverIn.read();
		if (c == -1)
			throw new EOFException("connection closed");
		byte[] b = new byte[1];
		b[0] = (byte) c;
		v.addElement(b);

		// Wait for packets until timeout
		while ((c = serverIn.available()) > 0) {
			b = new byte[c];
			if (serverIn.read(b) != c)
				throw new EOFException("connection closed");
			v.addElement(b);
			len += c;
			try {
				Thread.sleep(50);
			} catch (InterruptedException e) {
			}
		}

		byte[] d = new byte[len];
		for (int i = 0; i < v.size(); i++) {
			b = (byte[]) v.elementAt(i);
			System.arraycopy(b, 0, d, k, b.length);
			k += b.length;
		}
		return d;
	}

	protected void connect(Socket socket) throws IOException {
		super.connect(socket);
		reader = new BufferedReader(new InputStreamReader(serverIn));
	}

	public void disconnect() throws IOException {
		super.disconnect();
		reader = null;
	}

	protected int getHeaderLength() {
		return header != null ? header.length : 0;
	}

	public void setHeader(byte[] header) {
		this.header = header;
	}

	/**
	 * @param header Hex representation of header
	 */
	public void setHeader(String header) {
		setHeader(
				ISOUtil.hex2byte(header.getBytes(), 0, header.getBytes().length / 2)
		);
	}

	public byte[] getHeader() {
		return header;
	}

	protected void sendMessageHeader(ISOMsg m, int len) throws IOException {
		if (m.getHeader() != null)
			serverOut.write(m.getHeader());
		else if (header != null)
			serverOut.write(header);
	}
}
